The perovskite-like SrBi_(2)Ta_(2)O_(9)(SBT)thin films have been fabricated on Si/SiO_(2)/Ti/Pt substrate by pulse laser deposition.The crystallization and ferroelectric property were clearly dependent on the annealin...The perovskite-like SrBi_(2)Ta_(2)O_(9)(SBT)thin films have been fabricated on Si/SiO_(2)/Ti/Pt substrate by pulse laser deposition.The crystallization and ferroelectric property were clearly dependent on the annealing time and temperature.The SBT thin film with fine grain size and well-saturated square hysteresis loop was obtained after annealing at 750℃ for 90min.Good ferroelectric properties were obtained from the SBT film annealed under this condition;Pr and Ec were 8.4μC/cm^(2) and 57kV/cm,respectively.展开更多
Variable-temperature transmission/absorption spectra are measured on As-doped Hgl-xCdxTe grown by molec- ular beam epitaxy. The nonlinear temperature-dependent shift of the absorption edge is also observed, which is s...Variable-temperature transmission/absorption spectra are measured on As-doped Hgl-xCdxTe grown by molec- ular beam epitaxy. The nonlinear temperature-dependent shift of the absorption edge is also observed, which is similar to our previous report on VHg （unintentionally）-doped HgCdTe. By referring to the empirical formulas of Eg（x,T）, the x value of the epilayer is calculated and its inconsistency between the extreme temperatures （e.g. 10 and 300 K） is discussed. The results confirm the assumption of the effect of shallow levels on the shift of the absorption edge, and suggest that the x value （or Eg） in intrinsic/extrinsic-doped HgCdTe should be determined by referring to as low a temperature as possible （e.g. 10 K）, and not the commonly used temperatures of 77 or 300 K, when the transmission spectrum should be employed. This can give brief guidelines for fabricating HgCdTe-related devices.展开更多
文摘The perovskite-like SrBi_(2)Ta_(2)O_(9)(SBT)thin films have been fabricated on Si/SiO_(2)/Ti/Pt substrate by pulse laser deposition.The crystallization and ferroelectric property were clearly dependent on the annealing time and temperature.The SBT thin film with fine grain size and well-saturated square hysteresis loop was obtained after annealing at 750℃ for 90min.Good ferroelectric properties were obtained from the SBT film annealed under this condition;Pr and Ec were 8.4μC/cm^(2) and 57kV/cm,respectively.
基金Project supported by the National Basic Research Program of China(Grant No.2007CB924901)the Shanghai Leading Academic Discipline Project,China(Grant No.B411)+3 种基金the National Natural Science Foundation of China(Grant Nos.60906043,60990312,and 61076060)the Shanghai Municipal Commission of Science and Technology Project,China(Grant Nos.09ZR1409200,10ZR1409800,and 10JC1404600)the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant No.20090076120010)the Fundamental Research Funds for the Central Universities,China(Grant No.09ECNU)
文摘Variable-temperature transmission/absorption spectra are measured on As-doped Hgl-xCdxTe grown by molec- ular beam epitaxy. The nonlinear temperature-dependent shift of the absorption edge is also observed, which is similar to our previous report on VHg （unintentionally）-doped HgCdTe. By referring to the empirical formulas of Eg（x,T）, the x value of the epilayer is calculated and its inconsistency between the extreme temperatures （e.g. 10 and 300 K） is discussed. The results confirm the assumption of the effect of shallow levels on the shift of the absorption edge, and suggest that the x value （or Eg） in intrinsic/extrinsic-doped HgCdTe should be determined by referring to as low a temperature as possible （e.g. 10 K）, and not the commonly used temperatures of 77 or 300 K, when the transmission spectrum should be employed. This can give brief guidelines for fabricating HgCdTe-related devices.
